Measuring patch thickness

[doulos]

How is everyone measuring their patch thickness. I have both calipers and a micrometer. How much pressure if any do you use when compressing the patch during measuring?

[Daryl]

With calipers, I close the jaws on the cloth and squeeze the jaws between forefinger and thumb as hard as I can and read off the measurement.
With this method, the 4 meters of 10 ounce denim I purchases last spring, measures .021" thick. I think Taylor gets the same measurement.
With the mic, I use the ratchet brrrrt and take the reading. This measurement will usually be .003 to .005" smaller than with the calipers, depending
on the cloth being measured.  The 12 ounce denim I measured with calipers at .030" and mic at .025". The 14 ounce, I measured at .034" with calipers and .030" with the mic.
I wash the cloth twice, one cycle with soap to remove the sizing in new material and one cycle without soap to make sure I get ALL the soap out of the material.
I have 3 sets of calipers and they all give different readings,, .001" apart.  Thus what someone measures as .022" for example, I might measure as .019, through
up to .023" or so, but that doesn't happen often.
Measuring cloth non-compressed is a waste of time,  as it will be compressed between the ball, the lands and the grooves.  In calibres up to & including .50, if there is no
compression in the bottom of the grooves, the patch will get burn marks by gas flow past it in the grooves.
I'm pressure sure that at .58 and larger, not sure about .54, there is enough obturation (expansion) of the ball upon ignition, to seal the bore with what I would call a weak
combination.
All of my guns shoot well with the current 10 ounce denim & did with the older 10 ounce denim I measured at .0225" with the calipers.
The red, while, drk blue, lgt blue mattress ticking that was even more accurate, we cannot find any more. It measured .0235", was exceptionally soft and loaded & shot beautifully.
This is it.

[doulos]

Thanks
I compress it. But your way would probably more consistent. And I also get smaller numbers from a micrometer.

[smylee grouch]

I do about the same thing thinking that when I load the round ball the patch is compressed about the same amount.

[Hungry Horse]

 I use an old Ames snap mic that always gives you the same pressure, so you're not measuring how hard you can squeeze the calipers.

Hungry Horse

[hortonstn]

I agree with Daryl  calipers

[Daryl]

I'm going to make a note here, that all material that mics .020, .021 or .022" even, does not give the feel same when loading.
Some, like the canvases are harder strands of thread and do not compress as much as say a denim. The mattress ticking
I showed is VERY soft & actually loads easier than the .021" 10 ounce denim. It's weird, but it happens.

edited first sentence for clarification

[P.W.Berkuta]

I just purchased some 10 oz. cotton duck, some 7 oz. cotton duck, and cotton pillow ticking from Walmart. I washed them with laundry soap then dried them in the dryer. I then measured them with a digital caliper applying a moderate amount of pressure to compress. Here is what I got for thickness:
The 10 oz cotton duck = 0.027" - 0.028"
the 7 oz cotton duck = 0.018 - 0.019"
the cotton pillow ticking = 0.012" - 0.013"
I lubed strips of each of the above cloths with a blend of beeswax/lard/peanut oil. and then measured them again and found no change.
I also lubed another bunch with Mr. Flintlock's liquid lube and then measured them again and found no change.
Your milage may vary

[doulos]

With calipers, I close the jaws on the cloth and squeeze the jaws between forefinger and thumb as hard as I can and read off the measurement.
With this method, the 4 meters of 10 ounce denim I purchases last spring, measures .021" thick. I think Taylor gets the same measurement.
With the mic, I use the ratchet brrrrt and take the reading. This measurement will usually be .003 to .005" smaller than with the calipers, depending
on the cloth being measured.  The 12 ounce denim I measured with calipers at .030" and mic at .025". The 14 ounce, I measured at .034" with calipers and .030" with the mic.
I wash the cloth twice, one cycle with soap to remove the sizing in new material and one cycle without soap to make sure I get ALL the soap out of the material.
I have 3 sets of calipers and they all give different readings,, .001" apart.  Thus what someone measures as .022" for example, I might measure as .019, through
up to .023" or so, but that doesn't happen often.
Measuring cloth non-compressed is a waste of time,  as it will be compressed between the ball, the lands and the grooves.  In calibres up to & including .50, if there is no
compression in the bottom of the grooves, the patch will get burn marks by gas flow past it in the grooves.
I'm pressure sure that at .58 and larger, not sure about .54, there is enough obturation (expansion) of the ball upon ignition, to seal the bore with what I would call a weak
combination.
All of my guns shoot well with the current 10 ounce denim & did with the older 10 ounce denim I measured at .0225" with the calipers.
The red, while, drk blue, lgt blue mattress ticking that was even more accurate, we cannot find any more. It measured .0235", was exceptionally soft and loaded & shot beautifully.
This is it.

Just measured some bull 10 oz bull denim fabric that miced  out much smaller with your method of compression. About .016
This stuff might not be what was advertised when I ordered it to try.

[P.W.Berkuta]

Mr. doulos where did you buy that .016" material?

[doulos]

Bought from a vendor on Amazon. Just washed and wife put it in the dryer. I usually just hang it up. It shrunk and seems tighter and now measures larger when I compress the calipers. I was compressing them fairly hard and was reading .019-. .020. Im not sure why I measured that small before washing. It could have been operator error.

[Daryl]

I find washed and dried denim usually ends up .001" to .002" thicker than in the store.

[RichG]

However you measure, just do it the same whenever you purchase and you'll get what works for you. I would expect micrometers to read thinner than calipers. More force, smaller surface.

[Daryl]

With mine, I find the difference is usually .005".

[MuskratMike]

Why does it matter how or what tool you use as long as once you find the thickness your gun likes you use the same tool? I would always wash and dry the fabric to make sure it hasn't changed significantly.

[Daryl]

Consistency, though art a jewel.

[grouse]

I use a micrometer,what i have been doing is adjusting pressure until i cant pull it
from the jaws then reading the measurement.

[Daryl]

Repeatability is what is most important.